Elijah pratt and raymond graverend



PRATT & GRAVEREND.

Suspending Telegraph Wires.

Patented Feb. 27,1849.

.UNITED STATES PATENT OFFICE,

ELIJAH PRATT AND RAYMOND GRAVEREND, OF NEW YORK, N. Y.

IMPROVEMENT IN SUSPENDIN G TELEGRAPH-WlRES.

Specification forming part of Letters Patent No. 6,149 dated February27, 1849.

To all whom it may concern:

Be it known that we, ELI-TAR PRATT and RAYMOND GRAVEREND, of New York,in the county of New York and State of New York, have invented certainnew and useful Improvemen tsin SuspendingTelegraph-Wires forGreatDistances; and we do hereby declare thatthefollowingisafull,clear,andexactdescriptionofthe principle orcharacter which distinguishes them from all other things before known,and of the usual manner of making, modifying, and using the same,reference being had to the accom panying drawings, in which- Figure l isa side elevation of the suspension-posts and gum-elastic support. Fig. 2is a method of taking up the slack of the wire. Fig. 3 is a modificationof the same.

The nature of our invention consists in suspending a stretchedgum-elastic band, cord, or tube on posts or other suitable permanentfixtures, on or through which a wire is suspended in the air fordistances of great length for the passage of telegragh-wires acrossrivers, and in other similar situations.

By experiment we have found that a gumelastic tube or cord stretched tofive times its length when in its normal state will suspend a greater.weight than any metallic or other substance according to its weight withwhich we are acquainted, and that a tube or cord stretched to the degreeabove named, when sustained on posts in a horizontal line, will, inconsequence of its contractile power, remain in a straight line, ornearly so, and be capable of sustaining a small wire, sufficient toconvey the current for telegraphic purposes, which passes through it ifit is hollow, or is fastened to its outside in any convenient way. Thiselastic band'will, of course, be subject to be somewhat stretched outand swayed by the wind, and consequently if the wire was made rigid, itwould be liable to be broken.

To obviate this difliculty we either coil a portion of the wire into aspiral form at certain intervals, as shown at a, Fig. 2, or we extend itdown in a loop at either end, as represented at b, Fig. 3, in whichlatter case we suspend a sufficient weight to it to enable it to recoverposition when the elastic cord comes back to place.

Having thus fully described our improvementand its modification, what weclaim therein as new, and for which we desire to secure Letters Patent,is

Suspending telegraphic wires across rivers by means of a stretchedgum-elastic band or tube, substantially in the manner and for thepurpose set forth.

ELIJAH PRATT. RAYMOND GRAVEREND. Witnesses to the signature of E. Pratt:

J. J. GREENOUGH, WVM. GREENOUGH. Witnesses to the signature of R.Graverend JOHN G. ADAMSON, JAMES F. FINEGAN.

